Gree LSQWRF35VM/NaA-M, Service Manual

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113
Unit Installation
4.7 Maintenance
4.7.1 Requirements for maintenance
The unit has undergone a series of strict tests prior to delivery to ensure qualified performance,
however, in order to keep reliable performance and extend its service life, the unit should be maintained
routinely and periodically by the qualified service personnel.
Routine maintenance items
Is there any unusual noise and vibration?
Is there any unusual noise and vibration for the compressor in operation? Is there any unusual smell?
Do the operating pressure, voltage and current keep normal? If not, figure out the cause and then
eliminate it?
Are all temperature sensors and pressure transducers installed securely?
Periodic maintenance items
Is any wiring loosened and insulated securely?
Does any electric element work reliably? If not, change it timely?
Does any throttling valve and control valve leaks? Can any valve be opened or closed flexibly? Is any
filter clogged?
Is the temperature setpoint proper?
Is there a large amount of condensate at the chilled water pipe or the condensate pipe? Is insulation
layer damaged?
◆
Requirements on water quality and cleaning
Industrial water used as chilled water produces little scale, but well or river water will bring much scale,
sand and other sediment which then would block up the chilled water flow and make the evaporator frozen
up. Therefore, it is necessary to filter or chemically soften water before it flows into the water system and
also take analysis to quality. Once it is found water quality is dissatisfactory, and then only industrial water
is available.
Water quality requirement
Items
Cold/hot water Trend
Circulating
water
Makeup
water
Corrosion Scalelike
sediment
Basic
items
pH (25°C) 6.8-8.0 6.8-8.0 ○ ○
Electrical
conductivity
(25°C)
μs/cm <400 <300 ○ ○
Cl- mg (Cl-)/L <50 <50 ○
SO
4
2-
mg (SO
4
2-
)/L <50 <50 ○
Acid consumption
(pH4.8)
mg (CaCO
3
) /L <50 <50 ○
Total hardness mg (CaCO
3
) /L <70 <70 ○
Other
items
Fe mg (Fe) /L <1.0 <0.3 ○ ○
S
2-
mg (S
2-
) /L Undetectable Undetectable ○
NH 4+ mg (NH 4+ )/L <1.0 <0.3 ○
SiO
2
mg (SiO
2
)/L <30 <30 ○
NOTE: “○” indicates possible corrosion or scaling.